The present disclosure relates to the field of display technology, and particularly to a pixel circuit and a driving method thereof, and a display device.
With the development of display technology, Organic Light emission Diode (OLED) as a current-type light emission device, is increasingly being used in the high performance display field, because of its advantages of self-emission, fast response, wide viewing angle, and being manufacturable on a flexible substrate and the like.
An OLED display device includes a plurality of OLED pixel circuit structures. The OLED pixel circuit structure includes an OLED and a plurality of driving transistors. The OLED pixel circuit controls current flowing through the OLED with the driving transistors. The OLED pixel circuit generally includes two driving transistors, one capacitor and one OLED. The two driving transistors are capable of generating a driving current for driving the OLED according to the data voltage at a data signal terminal, and the value of the driving current is correlated with the threshold voltage (Vth) of the driving transistors.
In a case that the driving transistors of different pixel circuits have different Vths or the Vth of the same driving transistor drifts with time, the currents flowing through the OLED in the pixel circuit vary, even corresponding to the same data voltage. This causes low uniformity of display luminance of an OLED display panel and bad display effect.